Bunch charge uniformity controlling is very important for top-up operation of the storage ring.In order to monitor filling pattern and measure the bunch charge precisely,a PXI waveform digitizer-based data acquisition...Bunch charge uniformity controlling is very important for top-up operation of the storage ring.In order to monitor filling pattern and measure the bunch charge precisely,a PXI waveform digitizer-based data acquisition system has been developed to retrieve bunch charge information from BPM pickup signals.An effective sampling rate is extended to 400 GHz by waveform rebuilding technology,which overlays multi-turn data into single turn with real time sampling rate of 8 GHz.An on-line evaluation indicates that resolution and linearity of the charge measurement are better than 0.5% at input range of 0.5-12nC.展开更多
The top-up injection mode of Shanghai Synchrotron Radiation Facility(SSRF) needs precise measurement of the beam bunch charges.This is performed by an integration current transformer,but the beam current is too low to...The top-up injection mode of Shanghai Synchrotron Radiation Facility(SSRF) needs precise measurement of the beam bunch charges.This is performed by an integration current transformer,but the beam current is too low to neglect the background noise.In order to wipe out the noise coming from the ground loops,the adaptable polynomial fitting method is used to extract the baseline,instead of using the constant background or the linear background model. Test results show that the system resolution can be improved to <3%.展开更多
基金Supported by 100 Talents Program of the Chinese Academy of Sciences and national "SSRF project"
文摘Bunch charge uniformity controlling is very important for top-up operation of the storage ring.In order to monitor filling pattern and measure the bunch charge precisely,a PXI waveform digitizer-based data acquisition system has been developed to retrieve bunch charge information from BPM pickup signals.An effective sampling rate is extended to 400 GHz by waveform rebuilding technology,which overlays multi-turn data into single turn with real time sampling rate of 8 GHz.An on-line evaluation indicates that resolution and linearity of the charge measurement are better than 0.5% at input range of 0.5-12nC.
基金Supported by National Natural Science Foundation of China(11075198)
文摘The top-up injection mode of Shanghai Synchrotron Radiation Facility(SSRF) needs precise measurement of the beam bunch charges.This is performed by an integration current transformer,but the beam current is too low to neglect the background noise.In order to wipe out the noise coming from the ground loops,the adaptable polynomial fitting method is used to extract the baseline,instead of using the constant background or the linear background model. Test results show that the system resolution can be improved to <3%.
